If you try and update a submodule with a dirty working directory, you
get an error message like:
$ git submodule update
error: Your local changes to the following files would be overwritten by checkout:
...
Please, commit your changes or stash them before you can switch branches.
Aborting
...
Mention this in the submodule notes. The previous phrase was short
enough that I originally thought it might have been referring to the
reflog note (obviously, uncommitted changes will not show up in the
reflog either ;).
Signed-off-by: W. Trevor King <wking@tremily.us> Signed-off-by: Junio C Hamano <gitster@pobox.com>